Chemical Kinetics and Surface Processes
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Transcript Chemical Kinetics and Surface Processes
Recent Progress of SUNIST
HE Yexi, TAN Yi, XIE Lifeng, *FENG Chunhua, GAO Zhe, GUAN Xiaoyin, LIU Fei,
*WANG Long, WANG Wenhao, XIE Huiqiao, *YANG Xuanzong, ZENG Long,
ZHANG Liang
SUNIST United Laboratory
Department of Engineering Physics, Tsinghua University, Beijing 100084, China
*Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
12th International Workshop on Spherical Tokamak (2006), Chengdu, China
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Outline
SUNIST
Recent Progress of SUNIST
– First step of double swing Ohmic discharge
– Electron Cyclotron Wave Current Startup
2015/7/7
2
Future Plans
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
SUNIST
(Sino-UNIted Spherical Tokamak)
SUNIST Device Parameters (achieved)
– R/a: 0.3m/0.23m~1.3 (0.3/0.23,1.3)
– Elongation: 1.6 (1.6)
– Toroidal Field: 0.15T (0.15T)
– Plasma Current: 50kA (60kA)
– Flux Swing: ~60mV.s (30mV.s)
SUNIST United Laboratory
– Consists of
- Department of Engineering Physics,
Tsinghua University
- Institute of Physics
– Collaborated with
- Southwest Institute of Physics
- Institute of Plasma Physics
2015/7/7
3
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
SUNIST Device ( continue )
Magnets
Auxiliary Heating
– TF: 9.4kA/200V, 1.28F
– 2.45GHz/100kW/10ms ECW
– OF: 13kA/3kV, 13.3mF +(200V,
1.28F)
– VF: 1.5kA/1.2kV, 1(2)mF
+120V(450V), 476(18.8)mF
– (1MHz/300kW/10ms Alfven
Wave)
– 2 Rogowski probes, 9 flux
loops…
Vacuum
– TMP(1kl/s), Sputtering Ti
Pump(200l/s), Cryogenic
Pump(1500l/s, 4000l/s)
– Positive Temperature
Coefficient baking, Glow
Discharge Conditioning,
siliconization
Diagnostic
– electrostatic probes
– 8mm microwave
interferometer
– (soft x-ray detectors array)
(proposed)
– background: 5~6x10-5Pa
2015/7/7
4
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Outline
SUNIST
Recent Progress of SUNIST
– First step of double swing Ohmic Discharge
– Electron Cyclotron Wave Current Startup
2015/7/7
5
Future Plans
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
First step of double swing Ohmic
Discharge
Limitation of initial ramp-up ohmic discharge
– short duration of discharge
C
13.6mF
SCR
D
Coil
519uH
3000V
2015/7/7
6
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
First step of double swing Ohmic
Discharge
Modifications of the
circuit
– increase ramp-down rate
– shutdown the SCR
L’ 12uH
C’
500uF
3000V
SCR D
C
13.6mF
Calculations
SCR’
3000V
Coil
519uH
R
200mOhm
C'
2 I max 2 10kA 50s
0.5m F
UC'
2kV
1
Iohm,I’
2kV
dI '
L' U C '
10H
200A s 1
dt max
Vloop Lohm
1
8V 519H 1
R
200m
M ohm plasma I max
2.3H 10kA
2015/7/7
7
Imax
I’
50s
t
0
t
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Compare to normal ramp-up
ohmic discharge, >10kA Iohm
~30kA Ip
If loop voltage can be kept,
the plasma current can be
maintained.
15
10
5
0
-5
-10
4
6
8
10
12
14
16
18
0.8
0.6
0.4
0.2
0.0
4
6
8
10
12
14
16
18
10
8
6
4
2
0
4
6
8
10
12
14
16
18
4
6
8
10
12
14
16
18
24
Ip(kA)
Iv(kA)
With < 10kA Iohm, ~20kA Ip is
generated and a small flattop revealed.
Iohm(kA)
Vloop(V)
Test Discharges
16
8
0
time(ms)
2015/7/7
8
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Outline
SUNIST
Recent Progress of SUNIST
– First step of double swing Ohmic discharge
– Electron Cyclotron Wave Current Startup
2015/7/7
9
Future Plans
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
The Difficulties of Electron Cyclotron
Wave Current Startup on SUNIST
– microwave, 2.45GHz, <100kW,
~10ms
– continuous gas puffing,
~1x10-2Pa
– spike like current ~500A/300us
Bv (G)
28
30
32
34
36
38
40
42
44
46
48
50
52
28
30
32
34
36
38
40
42
44
46
48
50
52
18 28
30
32
34
36
38
40
42
44
46
48
50
52
30
32
34
36
38
40
42
44
46
48
50
52
0.04
0.00
Low toroidal field
low resonant frequency
0.6
0.4
0.2
0.0
0.08
Pin (kW)
Ip (kA)
Preliminary results in 2005
Ha (a.u.)
80
40
0
-40
12
6
0
28
low cutoff density
2015/7/7
10
Time (ms)
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Efforts of Improving ECWCS
top view of the movement of
the piezo valve
Wall condition control
– installed a cryogenic pump, CRYOPLEX 8LP, background gas pressure
was lowered to 5~8x10-5 Pa
– pulsed gas puffing, closer valve to
chamber distance, shorter puffing
duration (~2ms) and shorter filling
latency (~3ms)
the
piezo
valve
vacuum
vessel
conductor
– siliconization, SiH4 + He DC glow
discharge
~8ms
puffing
pulse
0
~30ms
power
pulse
t
~2ms
0
2015/7/7
11
~3ms
t
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Spiky still
Lower Bv cause oscillations of Halpha
and microwave reflection
2
4
6
8
10
12
14
16
18
2
4
6
8
10
12
14
16
18
0
2
4
6
8
10
12
14
16
18
16
8
0
0
2
4
6
8
10
12
14
16
18
24
18
12
6
0
2
4
6
8
10
0.6 2
0.4
0.2
0.0
4
6
8
10
2
4
6
8
10
2
4
6
8
10
50
40
30
20
10
0
2
1
0
0.2
0.0
0
2
4
6
8
10
12
14
16
Time (ms)
Inductive current startup by outer vertical field with
ECW assistance
2015/7/7
12
Ip (kA)
0.4 0
0.0
-0.4
-0.8
0
24
16
8
0
W
H, a.u.
Ip, kA
Iv, G
45
30
15
0
Pin
Vloop, V
H (a.u.)
Bv (G)
The ECWCS Results 2006
18
Time (ms)
Non-inductive current startup by ECW
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Reflection (%)
Effect of Bv, (Halpha emission in the mid
plane)
Bt
Reflection
R
Halpha
0
2
4
6
0
2
4
6
t1
12
14
16
18
8
10
12
14
16
18
10
0
Time (ms)
Reflection (%)
with Bv (~30G)
Reflection
Halpha
60
50
40
30
20
10
0
-10
-20
0
2
4
6
0
2
4
6
8
10
12
14
16
1
8
10
12
14
16
1
30
H(a.u.)
t2
Bt
10
20
Bt
Plasma
Drift
8
30
H(a.u.)
60
50
40
30
20
10
0
-10
-20
20
10
0
Microwave
Reflection
2015/7/7
13
Time (ms)
without Bv
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Possible Problems
Bad coupling of antenna
Transmission of the microwave is
poor, a lot of power reflected
Requires vertical field with positive
curvature
Vacuum Field of SUNIST
2015/7/7
14
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Outline
SUNIST
Recent Progress of SUNIST
– Reversed Ip Ohmic Discharge
– Electron Cyclotron Wave Current Startup
2015/7/7
15
Future Plans
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
Future Plans
Right hand circularly polarized
wave injection
Adding a capacitor bank in
order to reverse Iohm , and get
longer duration of Ip
C’
L’ 12uH
SCR’
Iohm
500uF
3000V
C
Ip
SCR
C’’
13.6mF
3000V
Iohm
R
200mOhm
1.28F
300V
0
t
SCR’’
2015/7/7
16
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org
The End
2015/7/7
17
Thanks
SUNIST
Sino-UNIted Spherical Tokamak, http://www.sunist.org